Asteroid Dodgeball part 2

Last week I presented the scary scenarios posed in an Earthly impact by a large meteoroid or asteroid.  This week I will look at technology that might help us avoid these scenarios.

But first, I want to mention an issue affecting amateur astronomers everywhere.  No, not light pollution, but that is a major issue.  I’m talking about the availability, actually the lack of availability of telescopes and associated equipment.  Seems COVID inspired lots of folks to purchase telescopes and other astronomy stuff.  At the same time, COVID caused the shut down of manufacturing facilities worldwide.  The result, every outlet for astronomy gear sold out and could not get more. It’s called “indefinite backorder” for most telescopes and accessories beyond beginner models.  Order a nice telescope now but be ready for a notice not to expect it until next year.  I know, boo-hoo, first world problem, eh?  It is, and as such it is just an annoyance.  We need to keep perspective. But it is annoying.

Getting back to the end of the world as we know it, or even the extinction of human life by a massive impact. Let’s see if we can prevent that.

So far, we’ve cataloged and track, we believe, greater than 90% of Near-Earth Objects (NEOs) that are larger than 140 meters in diameter and might be on an Earthly collision path. Can we get to 100%?  We don’t know what we don’t know, so probably not.  The universe is full of surprises.  Can you say Oumuamua?

What to do when one is on a collision course with Earth?

Blow it up?  No, many asteroids and comets are loose collections of debris and will shatter into smaller missiles, most still headed this way.

Change its trajectory? This appears to be the most satisfactory solution because there are numerous ways to achieve it.

-Send a heavy spacecraft parallel to the object in such a way the spacecraft’s mass (gravity) deflects the objects trajectory slightly.  We will need a very long lead time for this to succeed.

-Shoot the object with lasers or focused sunlight, causing it to heat and expell jets of vapor, acting as little thrusters.  For the future, and for comets only.

-A solid asteroid might be nudged out of trajectory with a powerful spacecraft’s thrusters

-Slam into the object with a spacecraft, changing its trajectory.

-Explode a nuclear bomb close enough to the object to change its trajectory but far enough away not to shatter it.  Tricky business.

NASA has a “Slam into the Object” mission planned for launch later in 2021 or early 2022.  It’s called DART (Double Asteroid Redirection Test) and the plan is to smack into Dimorphos, the moonlet of asteroid Didymos.  In theory the moonlet’s orbit will change, altering the asteroid’s trajectory as well.  Hope it works.

What’s in the Sky?

June 13; 45 minutes after sunset; west-northwest: A crescent Moon sits above Mars sharing the sunset sky.